First, go try it. The odds are pretty good that you own WoW, SC2, Diablo 3, which I think means you can get into the beta. It even pays you to play it. With in-game currency, of course.

This is an easy game to get started in. There are pre-made decks with starter cards. You can unlock heroes just by beating them in practice mode. You'll get flooded with gold early on, so you can expect to buy a lot of packs in your first few days. It slows after that, though it's still at a "fun" rate, in that you can get a pack about very other day.

It is not, however, an easy game to win in. Individual cards are not balanced. Your opponents, having played longer, will have cards that you can only dream of. Yet you can still win.

Luck is a huge component. If you get cards in the right order early on you can take control of the board and start hammering away at an enemy. If not, then the same can happen to you.

Games can turn around extremely quickly. This is not Magic: The Gathering where you have counterspells, blocking, or much of any ability to respond. If someone is rolling you over on their turn, you cannot stop them. The closest to a counter are Secrets, spells that you cast on your turn but which are triggered by a particular effect. For example, Frost Armor will give armor to the mage when they are attacked.

The result is that it can be hard to get any sense for how a game is going. You can be on the verge of death and facing a full board, only to draw a holy nova and completely turn things around. Card synergies can be impressive, such as a Northshire Cleric and a Darkscale Healer resulting in tons of card draw. A full hand means more ability to deal with what just happened.

Here's an example of how things can turn around very quickly, and how much luck can change things:

I'm playing against a warlock. We're going back and forth, but his Dread Infernals have caused a lot of damage, both with their battlecry and their heavy attack. I'm facing one and another demon, so I'm in trouble, but with a little luck I can use nukes and taunting minions to survive. It's not game over, at least not yet, though things do not look favorable. Then he draws Void Terror, which is just a 3/3, but it destroys adjacent minions and gains their attack and health, so now it is extremely powerful and tough. In two turns it can kill me. Even if I get lucky and draw cards with taunt the best I can do is stall. Or draw mind control. Yep, the very next turn that card comes out, and just in time for the 10th mana crystal. I steal the minion. The warlock is almost guaranteed to lose. He life taps, either to hasten the end or in hopes of getting something that can save him. It just puts him in kill range.

If I had not drawn the mind control it would have been game over. Or if he had not drawn the infernals. Or if I had gotten some of my heavier taunters. And so on. The game can be an endless string of what-ifs and you just have to hope that your luck with average out well in the end. And get a lot of card draw. But even that can kill you; with only 30 cards you can burn through a deck surprisingly quickly, especially as a warlock.

You might have noticed that this is all about priest cards. I've found that I very much enjoy playing the priest deck. The mage and paladin decks are pretty good too. I couldn't easily pick a favorite among them. That's a good thing, even if it makes it harder for me to decide which cards to disenchant. On that note, I don't know how much I like the crafting system since it relies on destroying cards at a very inefficient rate to make others, which is terrible for a loss-adverse person like me. I consider that a small part of the game and hardly a game-breaker.

One last thing to remember: Order of operations is critical. You can't heal a minion before it takes damage (well you can, but it does nothing), so my favorite card, Northshire Cleric, means that I have to get my minions injured first. A card like the Gurubashi Berserker has a fairly high health pool, so it can be hard to kill it without turning it into a raging monster of death. But, it starts with very low attack, so hit it with the things that you want to live, such as your important minions and hero. Save the burn spells and disposable minions for when it would kill whatever it touches.

All in all, I find that Hearthstone is a game that is well-suited to casual play. The quests can be stored up, so you don't feel pressure to play every day. They offer a choice of heroes, so you shouldn't often be pressured into ones you dislike (I'm pretty awful at rogue). Matches don't take a terribly long time. Even without spending money you can improve your decks. And the closest thing to trash talk is the person who emotes "well played" before they've actually guaranteed their victory.